1. Field of the Invention
The present invention relates to yellow toners used in recording methods such as electrophotographies, electrostatic recording methods, magnetic recording methods, and toner jet methods, and image forming apparatuses using the yellow toners.
2. Description of the Related Art
In recent years, color images have spread widely and the demand for high-quality images has been raised. In digital full-color copying machines and printers, color-image manuscripts are color-separated by each color filter of blue, green, and red, and thereafter, latent images corresponding to the original images are developed using each color developer of yellow, magenta, cyan, and black. Therefore, the coloring power of a coloring agent in the each color developer resultantly largely affects the image quality.
The reproduction of color spaces including the Japan Color in print industries and AdobeRGB in DeskTop Publishing (DTP) is becoming important. For the reproduction of the color spaces, a method is known in which a dye having a broad color gamut is used in addition to improvement of dispersibility of a pigment.
Typical examples known as yellow coloring agents for toners are isoindolinone, quinophthalone, isoindoline, anthraquinone, and compounds having an azo skeleton or the like.
Recently, examples are disclosed which use a pyrazole skeleton excellent in color properties and excellent in light resistance (see Patent Literatures 1 to 3).